How would you go about converting a center fire Hepburn action to rim fire? Since there is no link from the lever to the block would it require a new block?
Just curious. I know Walker's have been built in the past by some folks.



JMH

DZ Arms used to build some 22 Hepburn 
rifles. I don’t see where they do on their website anymore. You might get some information from them. (You need to Login or Register to view media files and links)

you can get a rimfire breech block from C,sharps arms for the standard hepburn. I cant see how a rim fire in the standard hepburn would be any more of a pain than it is in a high wall and i believe there were a decent amount of originals chambered in 22 rimfire.

the walker, hepburn is a whole different animal. there is a link between the underlever and the breech block in the walker. Also an additional screw in the side of the receiver that causes the breech block to tilt back pushing the hammer to full cock as it does. because of this the extracted rimfire case could fall into the open action with the tilted breech block.

There's a simpler way to convert and not alter the action. Plus you can always switch back to a CF easily!
Oldtime gunsmiths simply turned and threaded the barrel shank offset 1/8" so the CF firing pin struck the edge of the .22 shell. I have two Ballard rifles done this way and they work great!

jhm wrote on Sep 30^th, 2024 at 11:38pm:


I'm no machinist, but was told it simply takes a 4 jaw chuck on your lathe and adjusting the jaws to 1/8" off center before turning the round shank. Then thread it as you would any barrel and index it to align at 6 or 12 o'clock.

Here's a link to a YouTube video put out by the American Custom Gunmaker Foundation.
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In the video I'm doing an offset chamber for a two barrel set on a Winchester takedown. The video also covers relieving the threads for the takedown.

the idea of the offset bore always bothered me. not that I'll ever do it, but just thinking about them I wondered if saving the breechblock by offsetting the bore, did you just make even more hassle than coming up with an entirely different extractor geometry? Psshaw! what do I know?

calledflyer wrote on Oct 1^st, 2024 at 5:12pm:


It's not just saving the breech block Pat, it's also being able to build a switch barrel rifle and use the same firing pin and block. Plus just turning the barrel offset only requires a 2nd extractor to fit the .22RF and one for whatever CF cartridges.
I personally think whoever thought it up was pure genius.

So much information generated from a simple question asked...





JMH

Here's a picture of the breech end of the barrel showing the extractor setup. This was one of my test pieces, so it's a little rough.

buchsenmacher wrote on Oct 1^st, 2024 at 3:55pm:

Excellent video. Thanks for sharing.  Learned a couple of tricks (I hadn't previously thought of like using the mill to turn the offset shank) for this old dog. 

It's not just saving the breech block Pat, it's also being able to build a switch barrel rifle and use the same firing pin and block. Plus just turning the barrel offset only requires a 2nd extractor to fit the .22RF and one for whatever CF cartridges.
I personally think whoever thought it up was pure genius. [/quote]

I wasn't intending to say it was a poor idea, Vall, but whether the idea was worth it financially or in field service. If the extractor needs to be swapped out, why not just use a centered barrel, because the block is removed anyhow. Save the work of off-center boring. Hope that makes sense-- Like I said, just a non-machinist guy wondering how'n heck that idea got started.

I owned a converted Hepburn, originally a 45/70. Builder filled in the bottom of slot on the left side of breachblock so the screw that limits travel would stop the breachblock coming up at the exact point at which the firing pin would hit the lower rim of the 22LR. 

Slick and reversable

I copied the breech block on one of Tony's Walker's.  Here it is with the block down, has a loading ramp, followed by a picture of it at battery.  Transfer bar so the firing pin is straight on - striking at 6 o'clock.  Loading and removing still has it's challenges but it's better than the original design.

Aw guys I don't need to be seeing this. I got enough going on. I got a Borchardt build in progress and a Ballard and Farquarson kit ordered from Rodney. I don't need to be ordering a Hepburn kit too... Have to say much needed information if your going down that road though.


JMH

Here's a little drawing I made of my Zettler Bros. Ballard barrel. As you can see the bore runs centered to the exterior barrel dimensions, with only the threaded shank turned 1/8" off center to the rest of the barrel. Not at an angle.
The shank is 1/8" offset to the rest of the barrel, and only needs an extractor change when switching to CF or RF barrels.

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LRF wrote on Oct 9^th, 2024 at 6:42am:


The only offset is the threaded shank, which is 1/8" offset. The way mine is setup the offset is located straight up, so when the octagon barrel is installed it's lower from the receiver top flat by 1/8", but sides are almost equal to the receiver width. A new forearm was made to accommodate the lower barrel location and fit the lower part of the action.

steel-pounder wrote on Oct 10^th, 2024 at 11:00am:


Well your method also requires the breech block and extractor to be removed, so I don't see any difference in what it takes to change barrels?
The method Zettler Bros. used on my Ballard does one major thing, it saves having to have a 2nd breech block for a .22RF barrel. To me that's a major expense for any single shot, and a forearm for each spare barrel is something almost every multi barrel setup has used for a long time.
There is no "jacking around" because the shank is offset. In a switch barrel gun the barrels are setup with a cross pin, or a setscrew ala Stevens, so barrels are simply spun off by hand, and it doesn't require any more work to have a centered shank or an offset shank.
Some brands of actions are much quicker to change barrels on a takedown system, like Ballard, Stevens, Winchester. A Hepburn is a bit more time consuming to remove the breech block, so doing that is going to be more involved regardless of what breech blocks are used.

Not being a machinist at all, I have no idea how the old masters dialed in a barrel to be .125" offset on the shank. But I don't see any reason that a bore being .001" or even slightly more or less offset on the shank of a .22 barrel would have a noticeable effect on accuracy? 
I only know my Zettler Ballard shoots better than my skills allow, and others who've shot it did better than I did. No way to tell how one of the brothers dialed in the offset shank, or cut it now? Wish I knew as it would answer how much jacking around they did to get it done.
Not sure why you think my  shorts are in a wad?

marlinguy wrote on Oct 11^th, 2024 at 11:35am:


I possibly just misread the tone of your post. My appologies. 

I know guys that will just chuck up a barrel in a three jaw and cut away. My ocd will not let me do anything than the absolute best that I am capable of doing and trying to do better than that.